GSquared (3/8/2011)
To a very large extent, DR planning will depend on specific business needs, hardware availability, skillset availability, resources available/obtainable, and SLAs/SLRs.Virtual machines can be part of a DR plan, but more often, they're part of a money-saving plan. They can help if a motherboard crashes, but they aren't really part of handling database corruption, I/O failure, power outages, facility damage/destruction, data loss due to developer/DBA incompetence/accident, et al.
I seriously recommend hiring a contractor who specializes in disaster prep and recovery and going over business needs, etc., with that person. It'll take some time and some (a lot of) work, but you'll end up with a better plan, more suited to your specific needs, than you will by asking a few questions on an online forum and getting a few short, generic answers.
If you can't go that route, then start with the basics. Tested backups, some sort of co-location in case of fire/earthquake/hurricane/civil unrest/etc., redundant power sources (tested, checked, fueled regularly), multi-channel SAN with appropriate RAID arrangements, logs on different I/O systems than data files, server redundancy (mirroring, log shipping, replication, clustering, VM, or some combination thereof), spare hardware (hot-swap drives and spare power supplies at the very least), and, most important, a plan that has been drilled and tested to see how long it takes to recover from various levels of server/database issue.
Those are all general. Hiring an expert will get you specifics applicable to your situation and your business, your budget and your geography, etc.
very good advice... DR is so dependent on your environment, your systems, your budget, etc etc that it is nearly impossible to answer here.
The above is a good starting point though